Process for the preparation of aromatic polyesters

Abstract

Aromatic polyesters are prepared by the transesterification of aromatic dicarboxylic acid dialkyl esters with diester derivatives of divalent phenols at temperatures of about 260° to 350° C. with removal of the resulting monocarboxylic acid alkyl ester from the reaction mixture.

What is claimed is: 
     
       1. Process for the preparation of aromatic polyesters comprising reacting at least one aromatic dicarboxylic acid dialkyl ester with at least one diester derivative of divalent phenol at temperatures from 260° to 350° C. and removing the resulting alkyl esters of the monocarboxylic acids from the reaction mixture. 
     
     
       2. Process according to claim 1 wherein the aromatic dicarboxylic acid dialkyl ester is dicarboxylic acid dimethyl ester. 
     
     
       3. Process according to claim 1 wherein the diester derivative of divalent phenol is diphenyl diacetate. 
     
     
       4. Process according to claim 1 wherein the aromatic dicarboxylic acid is selected from terephthalic acid, isophthalic acid or mixtures thereof. 
     
     
       5. Process according to claim 1 wherein the divalent phenol is bisphenol A. 
     
     
       6. Process according to claim 1 wherein the alkyl esters of monocarboxylic acids formed in the process are removed from the reaction mixture by distillation in a vacuum.